US4936654A
Expired / Lapsed
US
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Liquid crystal display device
Assignee: Sanyo Electric Co Ltd
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Filing: 1989-01-19
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Granted: 1990-06-26
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Expires: 2009-01-19
Abstract
Abstract A liquid crystal display device has substrates opposed to each other, a nematic liquid crystal layer having a positive dielectric anisotropy and homogeneously oriented to have a twisted structure where liquid crystal molecules are twisted with a twist angle from 180° to 300°, the nematic liquid crystal layer being held between the substrates, polarizers between which the liquid crystal layer is placed, and a phase plate placed between the liquid crystal layer and one of the polarizers. In this display device, a product Δn·d(PH) of a birefringent anisotropy Δn and a thickness d of the liquid crystal layer and a product Δn·d(PH) of a birefringent anisotropy Δn and a thickness d of the phase plate satisfy a relational condition: 0.0<Δn·d(LC)-Δn·d(PH)<600 nm.
Inventors
- 👤 Takeshi Suzaki
- 👤 Kenichi Narita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:14
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F2202/00; G02F2202/40; G02F2413/00; G02F2413/01; G02F2413/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
112 words
A liquid cyrstal display device comprising: substrates opposed to each other, a chiral nematic liquid crystal layer homogeneously oriented with respect to said substrates, said liquid crystal layer causing a birefringence, polarizers arranged with a spacing from each other, said liquid cyrstal layer being positioned in said spacing, and a uniaxial phase plate inserted between said liquid crystal layer and one of said polarizers, wherein a first product Δn·d(LC) of a birefringent anisotropy Δn and a thickness d of said liquid cyrstal layer and a second product Δn·d(PH) of a birefringent anisotropy Δn and a thickness d of said phase plate satisfy a relational condition: 0.0<Δn·d(LC)-Δn·d(PH)<600 nm; whereby said birefringence is compensated.
Claim 2
Dependent Claim
112 words
A liquid cyrstal display device comprising: substrates opposed to each other, a chiral nematic liquid crystal layer homogeneously oriented with respect to said substrates, said liquid crystal layer causing a birefringence, polarizers arranged with a spacing from each other, said liquid cyrstal layer being positioned in said spacing, and a uniaxial phase plate inserted between said liquid crystal layer and one of said polarizers, wherein a first product Δn·d(LC) of a birefringent anisotropy Δn and a thickness d of said liquid cyrstal layer and a second product Δn·d(PH) of a birefringent anisotropy Δn and a thickness d of said phase plate satisfy a relational condition: 0.0<Δn·d(LC)-Δn·d(PH)<600 nm; whereby said birefringence is compensated.
Claim 3
Dependent Claim
79 words
The liquid crystal display device in accordance with claim 1, wherein said phase plate is an uniaxially drawn resin sheet and the drawing direction has an angle within the range of 20° to 60° with a polarizing axis or an absorption axis of the polarizer adjacent thereto and a polarization axis of the related polarizer has an angle within the range of 20° to 60° with respect to the orientation direction of liquid crystal molecules adjacent to said polarizer.
Claim 4
Dependent Claim
37 words
The liquid crystal display device in accordance with claim 1, wherein said first and second products satisfy the following further relational conditions: 0.6 Δn·d(LC)+60 <Δn·d(PH)<0.6 Δn·d(LC) +210 nm with respect to Δn·d(LC)≧550 nm, for an improved contrast.
Claim 5
Dependent Claim
21 words
The liquid crystal display device in accordance with claim 3, wherein said display device is constructed for providing a negative display.
Claim 6
Dependent Claim
22 words
The liquid crystal display device in accordance with claim 3, wherein said liquid crystal layer has a thickness less than 10 μm.
Claim 7
Dependent Claim
20 words
The liquid crystal display device in accordance with claim 3, wherein said phase plate is an uniaxially drawn resin sheet.
Claim 8
Dependent Claim
61 words
The liquid crystal display device in accordance with claim 3, wherein said phase plate is an uniaxially drawn resin sheet and the drawing direction has an angle from 20° to 60° with a polarizing axis or an absorption axis of the polarizer adjacent thereto and is substantially perpendicular to the orientation direction of liquid crystal molecules adjacent to said phase plate.
Claim 9
Dependent Claim
73 words
The liquid crystal display device in accordance with claim 3, wherein said phase plate is optical uniaxially and an optical axis thereof has an angel from 70° to 110° with respect to the orientation direction of liquid crystal molecules adjacent to said phase plate and a polarization axis of the related polarizer has an angle from 30° to 60° with respect to the orientation direction of liquid crystal molecules adjacent to said polarizer.
Claim 10
Dependent Claim
38 words
The liquid crystal display device in accordance with claim 1, wherein said first and second products satisfy the following further relational conditions: (7.5×10.sup.-4)(Δn·d(LC)-400 nm).sup.2 +150 nm<Δn·d(PH)<(7.5×10.sup.-4)(Δn·d(LC)-400 nm).sup.2 +300 nm with respect to Δn·d(LC)≧550 nm, for an improved contrast.
Claim 11
Dependent Claim
21 words
The liquid crystal display device in accordance with claim 9, wherein said display device is constructed for providing a positive display.
Claim 12
Dependent Claim
22 words
The liquid crystal display device in accordance with claim 9, wherein said liquid crystal layer has a thickness less than 10 μm.
Claim 13
Dependent Claim
20 words
The liquid crystal display device in accordance with claim 9, wherein said phase plate is an uniaxially drawn resin sheet.
Claim 14
Dependent Claim
61 words
The liquid crystal display device in accordance with claim 9, wherein said phase plate is an uniaxially drawn resin sheet and the drawing direction has an angle from 20° to 60° with a polarizing axis or an absorption axis of the polarizer adjacent thereto and is substantially perpendicular to the orientation direction of liquid crystal molecules adjacent to said phase plate.
Claim 15
Dependent Claim
73 words
The liquid crystal display device in accordance with claim 9, wherein said phase plate is optical uniaxially and an optical axis thereof has an angle from 70° to 110° with respect to the orientation direction of liquid crystal molecules adjacent to said phase plate and a polarization axis of the related polarizer has an angle from 30° to 60° with respect to the orientation direction of liquid crystal molecules adjacent to said polarizer.
Claim 16
Dependent Claim
22 words
The liquid crystal display device in accordance with claim 1, wherein said liquid crystal layer has a thickness less than 10 μm.
Claim 17
Dependent Claim
20 words
The liquid crystal display device in accordance with claim 1, wherein said phase plate is an uniaxially drawn resin sheet.
Claim 18
Dependent Claim
61 words
The liquid crystal display device in accordancde with claim 1, wherein said phase plate is an uniaxially drawn resin sheet and the drawing direction has an angle from 20° to 60° with a polarizing axis or an absorption axis of the polarizer adjacent thereto and is substantially perpendicular to the orientation direction of liquid crystal molecules adjacent to said phase plate.
Claim 19
Dependent Claim
73 words
The liquid crystal display device in accordance with claim 1, wherein said phase plate is optical uniaxially and an optical axis thereof has an angle from 70° to 110° with respect to the orientation direction of liquid crystal molecules adjacent to said phase plate and a polarization axis of the related polarizer has an angle from 30° to 60° with respect to the orientation direction of liquid crystal molecules adjacent to said polarizer.
Claim 20
Dependent Claim
32 words
The liquid crystal display device of claim 1, wherein liquid crystal molecules in said chiral nematic liquid layer are twisted at a twist angle within the range of 180° to 300° .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |